/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_cmplx_mult_real_f32.c
*
* Description:	Floating-point complex by real multiplication
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupCmplxMath
 */

/**
 * @defgroup CmplxByRealMult Complex-by-Real Multiplication
 *
 * Multiplies a complex vector by a real vector and generates a complex result.
 * The data in the complex arrays is stored in an interleaved fashion
 * (real, imag, real, imag, ...).
 * The parameter <code>numSamples</code> represents the number of complex
 * samples processed.  The complex arrays have a total of <code>2*numSamples</code>
 * real values while the real array has a total of <code>numSamples</code>
 * real values.
 *
 * The underlying algorithm is used:
 *
 * <pre>
 * for(n=0; n<numSamples; n++) {
 *     pCmplxDst[(2*n)+0] = pSrcCmplx[(2*n)+0] * pSrcReal[n];
 *     pCmplxDst[(2*n)+1] = pSrcCmplx[(2*n)+1] * pSrcReal[n];
 * }
 * </pre>
 *
 * There are separate functions for floating-point, Q15, and Q31 data types.
 */

/**
 * @addtogroup CmplxByRealMult
 * @{
 */


/**
 * @brief  Floating-point complex-by-real multiplication
 * @param[in]  *pSrcCmplx points to the complex input vector
 * @param[in]  *pSrcReal points to the real input vector
 * @param[out]  *pCmplxDst points to the complex output vector
 * @param[in]  numSamples number of samples in each vector
 * @return none.
 */

void arm_cmplx_mult_real_f32(
    float32_t* pSrcCmplx,
    float32_t* pSrcReal,
    float32_t* pCmplxDst,
    uint32_t numSamples)
{
	float32_t in;                                  /* Temporary variable to store input value */
	uint32_t blkCnt;                               /* loop counters */

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */
	float32_t inA1, inA2, inA3, inA4;              /* Temporary variables to hold input data */
	float32_t inA5, inA6, inA7, inA8;              /* Temporary variables to hold input data */
	float32_t inB1, inB2, inB3, inB4;              /* Temporary variables to hold input data */
	float32_t out1, out2, out3, out4;              /* Temporary variables to hold output data */
	float32_t out5, out6, out7, out8;              /* Temporary variables to hold output data */

	/* loop Unrolling */
	blkCnt = numSamples >> 2u;

	/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
	 ** a second loop below computes the remaining 1 to 3 samples. */
	while(blkCnt > 0u) {
		/* C[2 * i] = A[2 * i] * B[i].            */
		/* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
		/* read input from complex input buffer */
		inA1 = pSrcCmplx[0];
		inA2 = pSrcCmplx[1];
		/* read input from real input buffer */
		inB1 = pSrcReal[0];

		/* read input from complex input buffer */
		inA3 = pSrcCmplx[2];

		/* multiply complex buffer real input with real buffer input */
		out1 = inA1 * inB1;

		/* read input from complex input buffer */
		inA4 = pSrcCmplx[3];

		/* multiply complex buffer imaginary input with real buffer input */
		out2 = inA2 * inB1;

		/* read input from real input buffer */
		inB2 = pSrcReal[1];
		/* read input from complex input buffer */
		inA5 = pSrcCmplx[4];

		/* multiply complex buffer real input with real buffer input */
		out3 = inA3 * inB2;

		/* read input from complex input buffer */
		inA6 = pSrcCmplx[5];
		/* read input from real input buffer */
		inB3 = pSrcReal[2];

		/* multiply complex buffer imaginary input with real buffer input */
		out4 = inA4 * inB2;

		/* read input from complex input buffer */
		inA7 = pSrcCmplx[6];

		/* multiply complex buffer real input with real buffer input */
		out5 = inA5 * inB3;

		/* read input from complex input buffer */
		inA8 = pSrcCmplx[7];

		/* multiply complex buffer imaginary input with real buffer input */
		out6 = inA6 * inB3;

		/* read input from real input buffer */
		inB4 = pSrcReal[3];

		/* store result to destination bufer */
		pCmplxDst[0] = out1;

		/* multiply complex buffer real input with real buffer input */
		out7 = inA7 * inB4;

		/* store result to destination bufer */
		pCmplxDst[1] = out2;

		/* multiply complex buffer imaginary input with real buffer input */
		out8 = inA8 * inB4;

		/* store result to destination bufer */
		pCmplxDst[2] = out3;
		pCmplxDst[3] = out4;
		pCmplxDst[4] = out5;

		/* incremnet complex input buffer by 8 to process next samples */
		pSrcCmplx += 8u;

		/* store result to destination bufer */
		pCmplxDst[5] = out6;

		/* increment real input buffer by 4 to process next samples */
		pSrcReal += 4u;

		/* store result to destination bufer */
		pCmplxDst[6] = out7;
		pCmplxDst[7] = out8;

		/* increment destination buffer by 8 to process next sampels */
		pCmplxDst += 8u;

		/* Decrement the numSamples loop counter */
		blkCnt--;
	}

	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
	 ** No loop unrolling is used. */
	blkCnt = numSamples % 0x4u;

#else

	/* Run the below code for Cortex-M0 */
	blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0 */

	while(blkCnt > 0u) {
		/* C[2 * i] = A[2 * i] * B[i].            */
		/* C[2 * i + 1] = A[2 * i + 1] * B[i].        */
		in = *pSrcReal++;
		/* store the result in the destination buffer. */
		*pCmplxDst++ = (*pSrcCmplx++) * (in);
		*pCmplxDst++ = (*pSrcCmplx++) * (in);

		/* Decrement the numSamples loop counter */
		blkCnt--;
	}
}

/**
 * @} end of CmplxByRealMult group
 */
